Thermomorphogenesis in Lilium Longiflorum

Abstract

Stem elongation and leaf orientation in Lilium longiflorum Thunb. were influenced more by the difference (DIF) between day temperature (DT) and night temperature (NT) than absolute DT or NT from 14 to 30 C. Plant height and internode length increased 129 and 382%, respectively, as DIF (DT‐NT) increased from –16 to 16 C as compared to only 15 and 58% when either DT or NT was increased from 14 to 30 C, respectively. Leaf orientation, defined as the angle between a line perpendicular to the stem and the line from the leaf base to the leaf tip, increased 43° (leaves became more upright) as DIF increased from –16 to 16 C. In contrast to plant height, internode length, and leaf orientation, leaf and flower length were influenced more by absolute temperature than DIF. Leaf and flower length decreased 32 and 14%, respectively, as NT increased from 14 to 30 C. DT had little effect on either leaf or flower length. The influence of DIF on stem elongation suggested that thermomorphogenesis was not a function of total plant carbohydrate or carbohydrate translocation. Instead, DIF appeared to influence the endogenous gibberellin content or the response of plant tissue to gibberellin. Similarities between thermomorphogenic plant responses and photomorphogenic plant responses suggested that these two processes may be related with respect to their perception and/or transduction.

Thermoperiodic control of stem elongation and endogenous gibberellins in Campanula isophylla

“…These studies showed that stem elongation in Campanula was influenced more by the difference between day and night temperature than by average daily temperature or absolute day or night temperature between 12 and 24~ Similar responses have been reported for other species as well, Fuchsia • hybridia (Tangerfis 1979), Lilium longiflorum (Erwin et al 1989), and Dianthus chinensis (Moe 1983).…”

“…The systematic error can be calculated by comparing the response of GA97 with the response of D2-GA ~ in the mass spectrometer. (Moe 1990) and some other species as well (Erwin et al 1989) suggest an involvement of GA in the thermoperiodic regulation of elongation growth. In addition to effects on the levels of bioactive GAs, changes in tissue sensitivity to GA can be influenced by environmental factors (Nick and Furuya 1993, Pinthus et al 1989, Reid and Ross 1991.…”

Thermo- and Photoperiodicity and Involvement of Gibberellins during Day and Night Cycle on Elongation Growth of Begonia x hiemalis Fotsch

“…These growth responses were similar under negative DIF conditions, probably because the negative DIF value was −4.5°C under SD and −9°C under LD. Exogenously applied GAs can eliminate the negative DIF inhibition of stem elongation (Erwin 1991, Ihlebekk et al 1995, Moe 1990, Myster et al 1997, Tangerås 1979, Zieslin and Tsujita 1988, shown here with GA 1 , GA 4 , and GA 9 . In relative values, the effect of applying e.g.…”

“…Recently, it has been shown that internode elongation is closely related to DT − NT (DIF) in many plant species (Erwin 1991, Erwin et al 1989, Moe 1990, Moe and Heins 1990). For strong growing cultivars of the short day (SD) plant Begonia x hiemalis negative (DT < NT) or zero DIF (DT ‫ס‬ NT) results in compact plants of good quality (Myster and Moe 1995, Myster et al 1997, Willumsen et al 1995.…”

The Response to Gibberellin in Pisum sativum Grown under Alternating Day and Night Temperature

“…In general, plants grow tall with long internodes when the DT is higher than the NT, whereas a short phenotype with short internodes is developed under a DT lower than the NT. These thermoperiodic responses have been utilized for control of plant height in commercial plant production in climatecontrolled conditions (Bakken and Flønes 1995, Erwin et al 1989, Moe 1994. The two opposite temperature combinations have been referred to as temperature regimes with a positive (positive DIF, high DT/low NT) and negative difference between DT and NT (negative DIF, low DT/high NT), respectively.…”